1. Technical Field
The present invention relates to a liquid ejecting head installed in a liquid ejecting apparatus such as an ink jet type recording apparatus and a liquid ejecting apparatus having the liquid ejecting head, and more particularly, to a liquid ejecting head which ejects a liquid from a nozzle by generating a pressure change in the liquid inside a pressure chamber by deforming an operation surface configuring a portion of the pressure chamber communicating with the nozzle and a liquid ejecting apparatus.
2. Related Art
A liquid ejecting apparatus includes a liquid ejecting head capable of ejecting a liquid from a nozzle as a liquid droplet and is an apparatus which ejects various types of liquids from the liquid ejecting head. As a typical example of the liquid ejecting apparatus, for example, an image recording apparatus such as an ink jet type recording apparatus (a printer) may be exemplified which includes an ink jet type recording head (hereinafter, referred to as a recording head) and performs recording by ejecting the liquid ink from the nozzle of the recording head as the ink droplet. Furthermore, the liquid ejecting apparatus is used to eject various types of liquids such as a color material used in a color filter of a liquid crystal display or the like, an organic material used in an organic Electro Luminescence (EL) display, an electrode material used for formation of the electrode and the like. Then, a liquid ink is ejected from the recording head for the image recording apparatus and a solution of each color material of Red (R), Green (G) and Blue (B) is ejected from a color material ejecting head for the display manufacturing apparatus. In addition, a liquid electrode material is ejected from an electrode material ejecting head for the electrode forming apparatus, and solution of the bioorganic matter is ejected from a bioorganic matter ejecting head for the chip manufacturing apparatus.
The recording head provided in the printer described above is configured such that the pressure change in the ink inside the pressure chamber is generated by introducing the ink from an ink supply source such as an ink cartridge into a pressure chamber (a pressure generation chamber) and by operating the pressure generation unit such as a piezoelectric element or a heating element, and then the ink inside the pressure change is ejected from the nozzle as an ink droplet using the pressure change (see, for example, JP-A-2011-194783). The recording head described above corresponds to the improved quality of the recording image and a plurality of nozzles are disposed in a high density (for example, a pitch corresponding to 360 dpi). Accordingly, the pressure chamber communicating with each of the nozzles is also formed in a high density and, as a result, a partition wall defining adjacent pressure chambers or each of flow paths other than the pressure chambers is likely to be very thin.
Here, for example, when the ink is ejected from a nozzle, the partition wall may be displaced to the pressure chamber side by the pressure change in the ink inside the pressure chamber due to the driving of the pressure generation unit. Regarding this point, the adhesive is swollen by the ink that is used and then the bonding strength thereof may be reduced in a configuration in which a substrate forming the pressure chamber and a member, for example, a nozzle plate, which is laminated on the substrate and defines a bottom portion of the pressure chamber, are joined by the adhesive. In this case, a fixing force of the lower end of the partition wall of the pressure chamber is decreased. Thus, there are concerns that when the pressure change is generated inside the pressure chamber while the ink is ejected from the nozzle, crosstalk may be generated that the partition wall is easily displaced by the pressure, loss of the pressure is as much generated, and ejection characteristics of the ink droplet such as decrease of flying speed of the ink droplet, decrease of the amount of the ink droplet, and the like are changed. In other words, when the ink is ejected from a plurality of nozzles adjacent each other, at the same time (when all is ON) and when the ink is ejected from one nozzle (when one is ON) alone (a state where the ink is not ejected from the adjacent nozzles, at the same time), the ejection characteristics such as the amount or the flying speed of the ink are varied.
In the related art, the liquid ejecting head has been used to eject an organic solvent-based (solvent-based) ink with enhanced weather resistance, more than the conventional water-based ink, is ejected. The organic solvent-based ink is likely to cause swelling of the adhesive compared to the water-based ink. In addition, the compressibility (the amount that indicates the degree of the change with respect to the original volume when the pressure of 1 [Pa] is applied under constant temperature) of the organic solvent-based ink is greater than the compressibility of water or water-based ink under the same environmental condition (the temperature and the atmosphere). In ejecting the ink having the compressibility greater than that of the water described above, there is a problem that deterioration of the crosstalk described above is further remarkable. In other words, as described above, in a case where the pressure inside the pressure chamber is increased and then the pressure acts on the partition wall, when the ink filled in the adjacent pressure chambers is the organic solvent-based ink, the reaction force of the organic solvent-based ink against the partition wall is small compared to the water-based ink. Thus, the partition wall is easily displaced (deformed) by the adjacent pressure chambers, and, as a result, the crosstalk is deteriorated.
In addition, the problems described above exist in the ink jet type recording apparatus having the recording head ejecting the ink and also exist in another liquid ejecting head and another liquid ejecting apparatus in which the liquid is ejected from the nozzle by driving the pressure generation unit and by generating the pressure change in the liquid inside the pressure chamber.